1. Field of the Invention
The present invention generally relates to a scanning system, in particular, to an optical scanning system.
2. Description of Related Art
In recent years, with the increase of the demand of personalized gene sequencing, the market of reagent detection of gene chips is also grown year by year. Except gene chips, the market of microarray biochips of mRNA, peptide, protein and antibody are also grown with time. Gene microarray chip is mainly formed by disposing deoxyribonucleic acid (DNA) microarray on glass or silicon wafer. Different complementary DNA (cDNA) or oligo-DNA are disposed on the positions of the gene bio-microarray chip, so as to mix with biological samples and standard control samples. In general, fluorescent dyes in different colors like Cy3 (green) and Cy5 (red) will be used to mark the biological samples and the standard control samples. When using excitation light sources in different wavelengths to excite fluorescent dyes, the corresponding fluorescences will be produced. By detecting the positions of the fluorescences, the sequences and the structures of DNA can be learned. Besides, by detecting the luminous intensity of the fluorescence, the concentration of DNA having specific structure can be learned.
In general, lots of test points are disposed on the gene microarray chip. For example, tens of thousands of test points are disposed on 1-inch×3-inches gene microarray chip, and the size of each test point is about 80 to 100 micrometers. For precisely interpretation and analysis of the gene microarray chip, the biochip scanner with high resolution is needed to use to interpret the image and signal strength of the biochip, so as to determine gene type or gene structure and its corresponding concentration. In addition, the biochip scanner has to include two or more excitation light sources for exciting different fluorescent dyes. Therefore, how to fast and precisely excite fluorescent dyes to detect the biochip in one test process and to obtain a large number of gene sequences related information, is the research focus of the field.